Similar to humans, rhesus monkeys (Macaca mulatta) have adapted to a wide geographic and climatic range. They are found in forests, rural areas, and in cities on the Indian sub-continent. This behavioral plasticity, which has allowed them to readily adjust to new environments, may be centered around their ability to select and avoid foods as necessary for survival. Also similar to humans cultural group membership (the troop), social class (dominance status), social network (kinship), family size/composition and family traditions play important roles in the development of eating patterns and food choice in monkeys. How does food selection vary with sex, age, and reproductive state of the individual? How does social status and kinship affect access to food sources, meal patterning or influence food selection strategies? Do these variables result in significant differences in the overall dietary composition or nutrient content of the diets? How do infant monkeys learn food selection patterns? The specific aims of this application are to evaluate the impact of five subject variables on animals' food selection and eating patterns in their natural environment: 1) individual age; 2) sex; 3) social status; 4) adult female reproductive state; and 5) maternal rearing style. The main subject group was a large, dominant troop of rhesus monkeys who had unlimited access to a diverse forest habitat in Nepal. Smaller, parallel data sets from provisioned monkeys who selectively forage (on Cayo Santiago) and a caged colony which receives only commercial diet will allow evaluation of these social variables under varying degrees of environmental constraint and evaluation of foraging in rhesus monkeys in terms of dietary self-selection for specific nutrients. Quantitative observations on focal animal behavior with rate, duration and volume of food consumed as well as nutrient analyses of the food items have been completed. Repeated yearly samples of mother/infant feeding behavior will provide the first description of the ontogeny of natural feeding in this species and the role of the mother as teacher. The long-term objective of this project is to assess the impact of social factors on food selection and nutrient intake. A secondary objective will be to provide information which can be applied to enhance captive environments for these important research animals.